Chemo Pharmacology I

What is the objective of chemo?

to prolong ‘useful life’ - not cure

What kind of treatments are available for cancer? (4)

surgery, radiotherapy, chemotherapy, euthanasia

What are some indications for chemo? (4)

• non-resectable tumours- generalised or metastatised

• delay metastasis

• adjunct to surgery

• treating relapses

Cancer cells occur when there is __________

inactivation of tumour suppression genes and activation of oncogenes

Cancer cells have uncontrolled _________ (4)

proliferation, loss of function/lack of differentiation, invasiveness, and metastasis

Cancer cells tend to be similar to or the same as the normal cells which mean they can interfere with ________ (3)

DNA (apoptosis), telomerase function, and overexpression of some surface receptors

What are some different ways drugs can interfere with cancer development? (5)

• interfere with DNA (apoptosis)

• interfere with mitosis

• interfere with blood supply

• interfere with growth factors

• interfere with immune system

Since anti-neoplasia drugs are not specific for cancer, what else can they kill?

• non-specific for cancer cells → will kill any rapidly dividing cells (bone marrow, gut mucosa, germ cells, hair follicles)

• most interfere with DNA synthesis

What’re some side effects of chemo?
(hint: BAAGi+ & surgical implication + etc)

• bone marrow suppression

• alopecia

• allergic reaction

• GIT upset (vomiting and diarrhoea)

• infertility/sterility

• teratogenesis

• impaired wound healing

• plus specific side effects

Chemo dosage is measured by

body surface area

List the 6 major types of chemotherapy drugs

(hint: AAAAP ; 3.5 antis + 2 agents + misc)

1. antimetabolites

2. cytotoxic/antineoplastic antibiotics

3. plant alkaloids/Antimicrotubule

4. sex hormones / antagonists (misc?)

5. alkylating agents

6. Also platinum agents

Alkylating agents work by

covalent binding of alkyl groups to cellular macromolecules resutling in DNA interstrand and intrastrand cross-links (i.e. crossbinding of DNA) → apoptosis

What are some Antineoplastic ABs used in chemo? (4)

• doxorubicin

• bleomycin

• dactinomycin

• mitoxantrone

What’re the four A’s of supportive therapy?

Analgesics: NSAIDs

Antiemetics: ondansetron and metacloprimide

Appetite stimultants: diazepam

Anabolic steroids

What are some safety protocols for handling chemo drugs? (10)

• wear protective clothing - gloves & mask

• buy ready made drugs or use fume cupboard for mixing drugs

• buy injections already made up

• avoid spillage or leaks

• avoid breaking tablets up

• dispose of faeces and urine - incinerate

• pregnant women should not handle drugs / animals being treated

• keep animals away from children

• hospitalise animals

• OSH guidelines cover vet use

What is Cyclophosphamide used for, what are it's side effects and what group of drug is it apart of?

It is an alkylating agent used for lymphomas and leukaemia. It can have the side effect of haemorrhagic cystitis and is immunosuppressive

What is the difference between Cyclophosphamide and Chlorambucil?

Chlorambucil does not have the side effect of haemorrhagic cystitis

What are Methotrexate and Cytarabine used for and what group are they apart of?

They are antimetabolites. Used for lymphomas, leukaemia and myeloproliferative disease.

What is Doxorubicin used for?

Used for carcinomas, sarcomas, lymphoma and bladder tumours

What are the side effects of Doxorubicin? (4)

1. Cardiotoxicity
2. Allergic Reactions
3. Nephrotoxicity
4. Irritant when injected perivascularly

What are Vincristine and Vinblastine used for and what group are they part of?

They are plant alkaloids/ antimicrotubule. Used for lymphomas, ICT, MCT and some sarcomas.

You are presented with a 7 year old boxer that has swollen submandibular lymph nodes, anorexia, weight loss and lethargy. What initial tests do you run?

CBC/Biochem and take a FNA or biopsy of the swollen lymph node

7 year old boxer that has swollen submandibular lymph nodes, anorexia, weight loss and lethargy

You diagnose it with lymphoma. How do we treat it?

COP Protocol - Cyclophosphamide, Vincristine (Oncovin), Prednisolone

COP Protocol is divided into 3 phases. What are these?

1. Induction therapy
2. Maintenance therapy
3. Rescue or late intensification therapy

What is involved in the induction therapy phase of the COP protocol?

• Vincristine/Oncovin IV on Day 1

• Cyclophosphamide on day 1-4

• Prednisolone twice daily

Done for 8 weeks

What is involved in the maintenance therapy phase of the COP protocol?

• Vincristine IV every 3 weeks

• Cyclophosphamide/Chlorambucil on days 1-4 every week

• Prednisolone every second day